Improvement in boiler-furnaces



UNITED STATES PATENT QEEICE.

AMOS B. SMITH, OF GENEVA, NEW YORK.

IMPROVEMENT IN BOlLER-FURNACES.

Specification forming part of Letters Patent No. 139,522, dated J une`3, 1813 application iled October 8, 1872.

following is a specification- My invention relates to that class known as horizontal flue-boilers; and it consists more especially in the. employment of a series of rocking grate-bars or rakers, which are also operated by the varying pressure of steam.

Figure 1 is a side elevation of a steam-generator having my improvements attached. Fig. 2 is a vertical longitudinal section of the same, the water-tank and a portion of the coal-reservoir being removed. Fig. 3 is a sectional elevation of the left-hand end of Figs. 1 and 2.

It is found desirable to have this class of steam-generators self-regulatin g as far as pos sible; and to that end I apply anautomatic device to close the draft-valve, and open the check-valve in the smoke-liuc, when the steam is raised above the desired pressure, and vice versa when it drops below it; and also a selfraker having a series of fingers which are thrown up between the grate-bars, when the steam pressure falls, thus clearing out the ashes, &c.

I use an ordinary horizontal due-boiler, A. The furnace or fire-box B may be made separately, and is arranged under the front end. The combustion-fine C passes under and to the rear of the boiler, opening into the chamber D. rEhe caloric current passes from chamber D through the boiler-fines F to chamber E, and thence out to the chimney or smokestack through flue G G. I place the airchamber H against chamber D. The former is provided with two air-fines, I, leading along each side of the boiler and down to the sides of the ash-pit P under the grate g. The pipe J, leading to chamber H, has a damper or airvalve, d, which is connected to the Hap-valve b by a lever, f. This lever is pivoted to the arm a, and rests in a notch or fork in the top of the stem s of the steam-valve in the cylinder h. The lever may be graduated, as shown at e, Fig. 1, and provided with a counterweight, W, whereby the airvalve d may be made to close at any desired pressure of steam and the valve b to open. The raker-bars k are connected to the bent lever k, as shown in Fig. 1, and the said lever is connected by the rod 1' to the valve-lever m, which is pivoted to the arm a', and is connected with the valve in the cylinder i, the same as the lever f before described is to the valve in cylinder l1.. The counter-weight w is designed to keep the lever k down, except when it is raised by the pressure of the steam. The extension of the lever 7c between the weight and the rod r, is provided as a handle by which to work the rakers by hand when necessary. The coalreservoir L I place over the front end of the boiler. and the curved chutes M lead down from the reservoir on either side of the boiler to the furnace B below; thus a portion of the radiant heat from the boiler heats the coal preparatory to being delivered into the fur nace. The water-tank Tis placed upon the elevated horizontal section G of `the smokepipe, from which, in a similar manner to the above, the water is heated before entering the boiler. The water-pipe P may be provided with any suitable cock by which to regulate the ow or supply to the boiler. The standards S support that portion of the smoke pipe and of the tank T. A flap-valve might be provided within or at the bottom of the chutes M, and operated by the pressure of the steam, similarly to the valves b and d, to regulate the supply of coal, if desired. I make the tire-grate g concave, as seen in Figs. 2 and 3, which, it is believed, will economize fuel in this class of boilers by bringing all the burning coal nearer t0 the boiler.

It will be seen that when there is no steampressure in the boiler, the draft-valve d is open, as shown in full lines in Fig. 2, and the checkvalve b is closed. The air to supply the iire enters through pipe J into drum H, thence down each side of the boiler through pipes I to the ash-pit under the grate. The caloric current passes through ilue C, under the boiler, to chamber D, through the boilerlues F, chamber E, (as indicated `by the arrows,) and smoke-flue Gr G to the chimney. The weight W is placed upon the lever f at a point to afford the desired pressure of steam, and when it rises above that, that end of the lever is forced toward the position shown in full lines in Fig. 1, thus closing the draft-[lues Jand I, and openingthe valve b. This makes a very sensitive regulator of the re. Should the latter get low on account ot' the aceumu` lation ot' ashes up`on the grate, the Weight w is allowed to drop by the decrease of the steampressure, and the fingers n of the rakers k are thrown up between the grate-bars g and clear them from ashes or cinders.

It is obvious that the smoke-due might be passed through or around the tank, if desired; and the same may be said of the coal-reservoir; but, for simplicity, the plans or arrangements shown and described are preferred.

`AMOS B. SMITH. Witnesses:

WM. S. LOUGHBOROUGH, PATRICK MGINTYRE. 

